1. Field
Embodiments of the present invention generally relate to semiconductor substrate processing systems. More specifically, the invention relates to a shielded lid heater assembly for a plasma processing system.
2. Background
In manufacture of integrated circuits, precise control of various process parameters is required for achieving consistent results within a substrate, as well as the results that are reproducible from substrate to substrate. As the geometry limits of the structures for forming semiconductor devices are pushed against technology limits, tighter tolerances and precise process control are critical to fabrication success. However, with shrinking geometries, precise critical dimension and etch process control has become increasingly difficult.
Many semiconductor devices are processed in the presence of a plasma. If the plasma is not uniformly positioned over the substrate, processing results may also by non-uniform.
Although conventional plasma processing chambers have proven to be robust performers at larger critical dimensions, existing techniques for controlling the plasma uniformity are one area where improvement in plasma uniformity will contribute to the successful fabrication of next generation, submicron structures, such as those having critical dimensions of about 55 nm and beyond.
The inventors have discovered that improvements to the design of heaters utilized to control the temperature of a lid of the processing chamber have a beneficial effect on plasma uniformity.